Commit 6602cebb authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: skbuff.c cleanup 



(skb->data - skb->head) can be changed by skb_headroom(skb)

Remove some uses of NET_SKBUFF_DATA_USES_OFFSET, using
(skb_end_pointer(skb) - skb->head) or
(skb_tail_pointer(skb) - skb->head) : compiler does the right thing,
and this is more readable for us ;)

(struct skb_shared_info *) casts in pskb_expand_head() to help memcpy()
to use aligned moves.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 86cac58b

net/core/skbuff.c

+15 −32
Original line number Diff line number Diff line
@@ -685,16 +685,10 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) 


struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)

{

	int headerlen = skb->data - skb->head;

	/*

	 *	Allocate the copy buffer

	 */

	struct sk_buff *n;

#ifdef NET_SKBUFF_DATA_USES_OFFSET

	n = alloc_skb(skb->end + skb->data_len, gfp_mask);

#else

	n = alloc_skb(skb->end - skb->head + skb->data_len, gfp_mask);

#endif

	int headerlen = skb_headroom(skb);

	unsigned int size = (skb_end_pointer(skb) - skb->head) + skb->data_len;

	struct sk_buff *n = alloc_skb(size, gfp_mask);



	if (!n)

		return NULL;
@@ -726,20 +720,14 @@ EXPORT_SYMBOL(skb_copy); 


struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask)

{

	/*

	 *	Allocate the copy buffer

	 */

	struct sk_buff *n;

#ifdef NET_SKBUFF_DATA_USES_OFFSET

	n = alloc_skb(skb->end, gfp_mask);

#else

	n = alloc_skb(skb->end - skb->head, gfp_mask);

#endif

	unsigned int size = skb_end_pointer(skb) - skb->head;

	struct sk_buff *n = alloc_skb(size, gfp_mask);



	if (!n)

		goto out;



	/* Set the data pointer */

	skb_reserve(n, skb->data - skb->head);

	skb_reserve(n, skb_headroom(skb));

	/* Set the tail pointer and length */

	skb_put(n, skb_headlen(skb));

	/* Copy the bytes */
@@ -791,11 +779,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, 
{

	int i;

	u8 *data;

#ifdef NET_SKBUFF_DATA_USES_OFFSET

	int size = nhead + skb->end + ntail;

#else

	int size = nhead + (skb->end - skb->head) + ntail;

#endif

	int size = nhead + (skb_end_pointer(skb) - skb->head) + ntail;

	long off;



	BUG_ON(nhead < 0);
@@ -810,13 +794,12 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, 
		goto nodata;



	/* Copy only real data... and, alas, header. This should be

	 * optimized for the cases when header is void. */

#ifdef NET_SKBUFF_DATA_USES_OFFSET

	memcpy(data + nhead, skb->head, skb->tail);

#else

	memcpy(data + nhead, skb->head, skb->tail - skb->head);

#endif

	memcpy(data + size, skb_end_pointer(skb),

	 * optimized for the cases when header is void.

	 */

	memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head);



	memcpy((struct skb_shared_info *)(data + size),

	       skb_shinfo(skb),

	       offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags]));



	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)

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